Determination of k‘−J‘ Correlations of Reaction Products by Fluorescence-Imaging Techniques. 1. Linearly Polarized Excitation Scheme

Abstract

A one-photon excited fluorescence detection scheme that employs fluorescence-imaging techniques is proposed to determine k′-J′ correlations of reaction products. To extract information of k′-J′ correlations from the fluorescence intensities of image patterns, a density matrix formalism is utilized to analyze both the linearly polarized and the circularly polarized detection schemes of a one-photon excited fluorescence process, in which a linearly polarized excitation laser is employed. Explicit fluorescence intensity formulas are given for various detection schemes and transition sequences. For the detection scheme that probes linearly polarized fluorescence photons, state multipoles of the density matrix of reaction products along various scattering angles θ, that is, population (F0 (θ)) and alignment parameters (F0 (θ), F1 (θ), F2 (θ), F0 (θ), F1 (θ), F2 (θ), F3 (θ), F4 (θ)), can be uniquely determined by 12 independent measurements of the intensities of fluorescence imagings as functions of probe angles and transition sequences. Experiments which measure circularly polarized fluorescence photons can provide information on orientation parameters (F1 (θ), F1 (θ), F3 (θ)) in the present detection scheme. Contributions of the individual term in the intensity formulas to the fluorescence imagings have been assessed by numerical calculations. A pattern recognition of fluorescence images of photofragments with v-J correlations has also been established.